


such sweet sin

by bigbootyborgias (grimgrace)



Category: The Borgias
Genre: F/M, Incest, but if you're watching the Borgias you're probably cool with it
Language: English
Status: Completed
Published: 2013-04-21
Updated: 2013-04-21
Packaged: 2017-12-09 02:43:39
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,627
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/769040
Author URL: https://archiveofourown.org/users/grimgrace/pseuds/bigbootyborgias
Summary: <blockquote class="userstuff">
              <p>Cesare doesn’t think to stop it as he kisses her back. Brings his head down to meet her lips more thoroughly, presses his fingers into her skin. It may send him to hell indeed, but for her he would gladly go to damnation.</p><p>Not her though. He would never let her go to such a place.</p><p> </p><p>(Post 3x03. Borgiacest Smut)</p>
            </blockquote>





	such sweet sin

**Author's Note:**

> I am so glad I didn’t write anything about how they got together I would have never done that episode justice. 3x03 was glorious, guys. Go watch it immediately. Still in a Borgia’s fic mind frame though, so I thought I’d write a bit of a follow up. Their affair, that is, before Lucrezia leaves for Naples :D
> 
> Written for the Anon user who prompted: 'Borgiacest Smut Please!! :)'

 

When he wakes the next morning, Lucrezia isn’t with him. She must have gone in the night, because the spot where she fell asleep beside him is cold. He would assume that it had all been a dream, but then there were bites on his chest that stung pleasantly, and a satisfaction in his body that couldn’t only be his imagination.

 

The guilt fills him seconds later. His sister, his beautiful sister, corrupted by him in such a way. It’s unthinkable, it’s _unforgivable._

 

He is glad that she is gone now, away from his bed from the evidence of their sin together. (He would have never been able to ask her to leave).

 

* * *

 

 

She and her new husband leave for Naples within a few days, and not for the first time where his sister is concerned, the knowledge leaves Cesare confused. It is probably best, he thinks that he stay away from her. To keep her safe from him has never been something to consider before but now?

 

And yet the mere thought of that distance again, of being forced from her company for so long, it makes him sick to his stomach. The feeling lingers in his stomach, mingles with the guilt he feels. Whenever he sees her he wants to reach out and grab her, pull her close and touch her skin again.

 

But that in itself makes him step away. Not to her. He won’t do this to her.

 

He is successful for a full day, before she corners him. She doesn’t spend the night after with him – too much suspicion would be catastrophic, even if the rumours already exist. And she has a new husband, after all, who requires her attention – and a son, who needs her even more.

 

But late on the second day, when the sun is just setting and everyone has headed to their rooms to prepare for the evening meal – she finds him. Pulls him into a small room in the palace, away from prying eyes.

 

There is a window in the room, facing the setting sun. It bathes the room in orange light, seemingly setting her golden hair on fire. The light makes her skin look luminescent, soft and playful and perfect. Her eyes are glinting, and her smile is brighter than the sun outside.

 

“You did not think to avoid me, did you Brother?” She asks, leaning close to him. She presses her hand to his chest, brings the other one up to cradle his neck. There she twists his curls around her fingers. She leans forward, breathing softly on his neck for a moment before pressing an open kiss there.

 

He can’t help it as his hands settle on her waist, as they pull her closer. His thumb grazes the underside of her breast, because he is wicked and can’t think to stop himself. His heart pounds on in his ears, the blood rushing through his body like he is suddenly in the middle of a battle. The voice in his head, his fathers, screams at him for his sins. His own voice argues back, like it always has.

 

He pulls her closer still.

 

“Never, Sis.” He breathes out.

 

She brings her other hands up now, and cups his chin. Her fingers are gentle as they map out the features on his face.

 

She leans forward, presses her body against him as she rises to her toes. She kisses him then, her lips grazing his, her tongue darting out to meet his.

 

He doesn’t think to stop it as he kisses her back. Brings his head down to meet her lips more thoroughly, presses his fingers into her skin. It may send him to hell indeed, but for her he would gladly go to damnation.

 

Not her though. He would never let her go to such a place.

 

He wonders if God would listen, if he told him that it was his actions that ruined her, not her own. She deserved to be in the sky with the angels – if she weren’t an angel already. (It was impossible to look upon her and believe her purely human like the rest of them. She was ethereal).

 

He pulls away with this thought on his mind. The God that he knows is not so merciful to listen. He would cast his sweet sister to hell as quickly as he would Cesare, and that is something that Cesare will not have.

 

“We can’t.” He whispers into her mouth, breathing her in the best he can before he has to inevitably give this up.

 

She drops back to flat feet, and looks at him with a face that breaks his heart. (What’s left of his black heart beats only for her, his mother and his father. His youngest brother, his nephew – the family he would be condemned to see them saved).

 

“Do you not love me then, Brother? Will you deny me like he did?”

 

Cesare wants to rip Alfonso’s head from his shoulders for doing this to his sweet sister. It would be an easy punishment as well, not the one that he deserves. For inflicting such insecurity on Lucrezia, the man ought to be damned.

 

He presses a kiss to her forehead this time, his fingers pressing at the nape of her neck. He can’t touch her hair – it is too intricately bound for him to risk ruining it.

 

“No.” He says softly, against her head. “I love you more than any man can.” He leans back and looks at her eyes. “But we _can’t._ ”

 

This same argument had not been so effective two nights ago, he reminds himself. Why he expected any different this time was beyond him.

 

She brushes his hair slightly.

 

“We are Borgias,” she says softly. “What is _one more_ sin?”

 

It is thanks only to the sudden sounds from the corridor outside that they part. Cesare would not have found the will otherwise, the consequences of being caught in this position enough to keep him thinking.

 

Lucrezia can obviously see it the moment the decision is made in his mind, and she smiles almost grimly, and steps away.

 

“I will miss you when in Naples,” she says quietly. “So much.”

 

She turns and leaves before he can respond, the words singing through his head. When she is _gone_. He’s made no friend of Alfonso, has no clear reason to visit her as often as he’d like. And his duties to his father and their papacy will always keep him in Rome.

 

It is another thing they share then, he thinks. He can’t think of a fate worse than having to stay away from her.

 

* * *

 

 

The people of his father’s house are lying to him. They’re avoiding him, trying to keep something from him. He gets it from Micheletto eventually – that’s why he pays him, after all. He does not have a man of his calibre in his pay so that everyone can lie to him.

 

On the other hand it is perhaps good that he finds out from his friend, because he isn’t sure that anyone else would have survived his reaction.

 

Micheletto is no stranger to violence, so he takes the new cut on his neck in his stride. The similar mark on Cesare’s neck – Micheletto is in his employ for a reason – only serves to make Cesare more angry as he storms to find his father.

 

The rumours are true this time. Alfonso’s declaration that the marriage was still unconsummated had brought the attention of the King of Naples, and something was to be done. Ferdinand is troublesome. The _honoured guests_ that he invited to Lucrezia’s wedding are as much a threat as Cesare’s words had been. And he has made it clear he will not abide any chance for a humiliation like Giovanni Sforza suffered.

 

No. Instead, Lucrezia would be humiliated, forced to consummate in front of an audience.

 

Surely this was a crime.

 

Rodrigo refuses to hear Cesare’s anger – and now it seems Lucrezia is the one avoiding him. All his father has to say on the matter is simple.

 

“The marriage will be confirmed legitimate, and Lucrezia will partake willingly – for the good of the family.”

 

There is nothing Cesare can do. Lucrezia seems far more able to avoid him than he could her, so he does not see her before it happens. He is not sure if he wants to – how can he face her and tell her that there is nothing he can do – short of taking her away from all of this? They could run away, in another life he supposes. But neither he or his sister could bare to leave his family, not his father or mother or Gioffre.

 

The day it happens, the Cardinals avoid him wherever he walks. He knows that they find this amusing, that they yearn to see Lucrezia Borgia laid out in front of them. But similarly, they know of the wroth they’ll face should he hear of it from their mouths. So their whispers stop whenever he is near, and start only as he walks away.

 

It makes his skin burn with anger, blood rising to the surface. His hand itches towards his sword, closer every second – and he trains with Micheletto outside for most of the day, to avoid the house and the people within it.

 

It is only just before it is set to begin, while he spars still with Micheletto, that he changes his mind abruptly. How could he consider leaving her at a time like this? He, who had promised to her since the day she was born that he would always protect her the best he could? How could he desert her now?

 

No. Instead of abandoning her, he would have to face it. Face the consequences of his failure to protect her, his inability to keep her safe.

 

He leaves Micheletto there (his manservant sees all and doesn’t hesitate when Cesare sheathes his sword and turns his back on him). He doesn’t enter the room when he arrives – instead he stands at the entrance, the door slightly open – enough to see her face when he looks in.

 

She looks back at him. Her body is rocking in time with her child of a husbands, the onlookers are muttering between themselves, chuckling and jeering softly. Not too loud – she is still the Pope’s daughter, after all – but there is a gloriously naked woman in front of them and the old men can only be expected to refrain for so long.

 

He will gut them all, Cesare vows in that moment. And any other man who presumes to look on her without her love.

 

He doesn’t like Alfonso, doesn’t trust him or his family. But he has never hated him before this moment. Lucrezia had chosen a young man, one she could mould with her expectations and requests. He was harmless on his own, her young husband.

 

And yet, Cesare sees him thrusting (quick, hard, sharp – probably anxious to end the show as fast as possible) and his vision is blinded by red. He wants to set his sword deep between those shoulders, he wants to feel the man’s final breath leave him. Lucrezia deserves more than this boy – she deserves someone who will give her what she needs, what she wants. Gentle. Someone who would treat her with the respect that she is worthy of.

 

Her eyes are sad, but when she sees him something in them changes. It isn’t that she’s happy now, or glad that he’s here. But a determination lights up in her eyes, and her jaw clenches and she reaches up with her hand to clutch at Alfonso’s shoulder. Her fingers dig in there and suddenly Cesare can feel the tiny bruises that she left on his body. With every thrust of her husbands, he remembers her tight warmth.

 

And a tiny smirk comes to play on her features, as though she knows exactly what she’s doing to him in that moment.

 

She probably does.

 

He wants to flee from her, hide his desire from her because it’s just so _wrong_. But he promised her a long time ago that he wouldn’t leave her and he isn’t about to leave now – not while she faces what may be the most difficult trial of her life.

 

He leans against the frame of the door, folds his arms across his chest and smirks right back.

 

* * *

 

 

After that, it’s inevitable.

 

He finds her in her rooms this time, a renewed sense of surety in his movements. He knows why he’s here, and she knows just as well. And they’re both fine with it. A part of him worries that perhaps, after King Ferdinand’s sick show, she won’t want to be touched – but a bigger part of him demands that he make her his again, and he knows thats a part of him that she loves.

 

When he enters, she’s lying naked on her bed, resting back on her elbows and smiling at him. She’s cleaned, but there are bruises on her body – he knows they aren’t his because he would never mar her perfect skin like this.

 

She watches as his fists clench, and looks at herself, to see what has roused such anger. When she sees, she smiles.

 

“He was nervous for people to watch,” she says casually, as though she doesn’t mind. She should mind – she shouldn’t ever be _marked_. “He was a virgin after all. How would you have liked to have your first time on display?”

 

Cesare moves to the bedside, without a moment’s thought to pretence. They both know why he’s here.  

 

“ _I_ would not have hurt you,” he says. He is hesitant here, you could say – but maybe it’s just slow. He takes his time as he lifts his hand to caress one of her bruises on her waist, where her husband gripped her so tightly.

 

Lucrezia raises a brow. “He looked to me for comfort.”

 

Cesare scowls. “He should have been comforting you.”

 

He thinks to her display again, to how those witnesses had laughed. He clenched his fist again, his fingers dragging across her skin, his knuckles brushing her stomach as he did so. She watches and smiles as it happens, and shifts slightly, moving her hand to rest on top of his. She presses gently until his hand is flat against her again.

 

“That’s for you to do though, brother. You comfort me.” She says softly.

 

He leans forward until his lips brush hers, but he doesn’t press further for a moment. He lingers there, breathes her in.

 

“Indeed,” he sighs into her lips before he kisses her.

 

She sinks down, her other arm coming away to clutch at his hair, her head falling into her cushioned pillow. He follows her, crawling forward until he is leaning over her, his arms bracing her head and looking down at her. Her hair is splayed out on the pillow, and she looks like Madonna must have. It’s breathtaking.

 

“Had you asked I would have killed everyone in that room, to save you from their eyes.” He whispers.

 

She kisses him again for a long moment, before releasing him. “It was for the family, Cesare.” She says softly. “I was happy to do it.”

 

He kisses her fiercely then, pressing her further into the pillows. She lets out a little noise of surprise, and then giggles against his lips as she threads her fingers further into his hair and opens her mouth wider for him. He feels as though he’s conquered a new land, as though he has to make it clear to everyone that it’s his.

 

“The family should not have asked that of you. No matter what _king_ demanded it. We should have cut him where he stood.”

 

Lucrezia clings to his neck like it’s the only thing she can hold onto. She leans up a little, brings her lips to his ear and bite the lobe. “I could feel their eyes on me – I could hear what they whispered.”

 

Cesare pressed his nose closer to her, nuzzling the space where her jaw and neck connected. “I should cut out their tongues.”

 

Lucrezia ‘ _hmms_ ’ in response to that then moves again, kissing him. It’s softer now, slow. She lets go of his neck with one hand to reach down to his waist. She grips the hanging material of his shirt and pulls it free, lifting it up and baring his skin to the cold night air. (It doesn’t feel cold at all, despite the bumps that erupt on his skin from the chill).

 

He leans back to pull the shirt off, reaching over his head to grab the back of the shirt and pull it away. He tosses it to the side, before leaning back down again. It was only a few seconds and already he misses the feel of her on his lips, so he remedies that quickly.

 

“Will you cleanse me of it, brother?” she asks in one of the rare moments that they pause for air. “Their perverted eyes still make my skin crawl.”

 

And any idea that she in uncomfortable makes him angry again. His hands, framing her head, clench in the blankets that she’s lying on.

 

He brushes his nose against her. “Could your husband’s touch not do the same?” he asks.

 

It’s almost a cruel question – he knows the answer as well as she does. If anything it is selfish, he asks only so that he can hear her say no. So that she can tell him that Alfonso’s touch is nothing to rival his – that _he_ is the one that she needs.

 

She sees right through him, and displaying the cunning of a Borgia, she responds.

 

“Make me feel like yours again, Cesare.” She says, ignoring any mention of her husband and pressing it to the side. He would have mentioned the move were it anyone else, but her words ignite something in him that is fierce and won’t be stopped.

 

Why would he want to stop?

 

He shifts his body slightly, so that he is no longer hovering over her but pressing his full body down against hers. She shifts automatically, like any woman would, her legs spreading to cradle him – but this is not any woman. This is Lucrezia Borgia, his ethereal sister, holding him so close to her. He can feel her warmth through his clothing – and suddenly he wishes he’d taken the rest of his clothes off before settling against her. He doesn’t want to pull away now to finish the job.

 

She rocks up against him – the same way she did against Alfonso earlier. The thought infuriates him and he leans down, finally giving her breasts the attention they deserve.

 

She lets out a soft laugh as he does so and rocks again.

 

“You play with fire, Sis.” He mutters against her chest.

 

She tugs on a piece of his hair, and smiles down at him. “You won’t burn me.”

 

She’s right. She’s always right. When he has nothing to say to that, she laughs again, before reaching down with her hands, grasping at his pants and belt. She unbuckles the belt and rips the leather away with quick and nimble fingers, tossing it to the same forgotten space that his shirt flew to. She doesn’t pause before reaching out again, pulling the front of his pants down and wrapping her small hand around him.

 

He lets out a muffled groan against her breast, and bites softly on the pink nipple as she begins to stroke him softly.

 

He lets his own hand descend then, ghosting down her body, brushing her soft skin until he comes to the golden curls at the apex of her thighs. He found her, parted her while her second hand tugged harshly on his hair and she let out a soft moan.

 

He glanced up at her as he finally touched her, and was able to catch the moment that she sucked in a sharp breath and bit her lip. Her eyes fluttered closed as his fingers slipped into her, running through her folds, up to the sensitive nub, which he avoided in favour of instead moving back to her centre.

 

Her grip on his tightened for a moment, and he groaned into her skin. It took him a moment but he moved further down, out of her grasp so that he could get a better angle at her pleasure.

 

She was wet, gloriously so. Just for him, a voice in his head chanted, while he coated his fingers. Without him to focus on, she let her head fall back onto the pillow again, closing her eyes and letting out a soft exclamation. “ _Fuck.”_

 

Her language took him by surprise. He had yet to hear his sister swear, and such words were not made for a mouth as pretty as hers. It fuelled his desire even more, and with a grunt of concentration he angled his fingers to move deep inside her.

 

Simultaneously, the siblings let out a groan – her at the feeling of his fingers, and him at the feeling of her. He’d been inside her before, his spinning mind whispered. And he would be again, her tight wet heat around him, engulfing him to the hilt.

 

She keens, pushing herself down on his fingers as he twists them inside her.

 

Watching her like this makes him throb like nothing else, yearn to seat himself inside her immediately. He’s so swollen that it almost hurts, and he’s glad that his pants are no longer fastened. To relieve some of the pressure, he presses himself against the mattress slightly. It doesn’t help, but he doesn’t want it to be over quickly – he knows what he wants for tonight. To wash her of all the other men who had watched her today, of her husband who had had to use her for his cousin’s desires. To make her his again, to see her take some pleasure from his touch.

 

His mouth drops to her breast again, to give him something else to focus on while his fingers press persistently inside her.

 

The sounds she makes now, by God. She whimpers, mewling, her hands curling into the fabric of the bed covers, her eyes closed in her ecstasy. She flutters around him, and he can tell that she’s close – her jaw clenches shut in the short moment right before his thumb finds _the spot_ and presses.  

 

Cesare feels his sister freeze under him. He moves quickly, leaning forward, touching her chin and bringing her head up so that she can look at him. Her eyes open with her jaw, a look of shock as his other hand rubs at her nub. He holds his gaze, her wide eyes captive as the rest of her body shakes, riding the waves of pleasure while her walls squeeze his fingers. Her hand moves out, grabs his forearm as the pleasure hits her.

 

A moan fills the room, loud – but he doesn’t worry that anyone could be listening. They will assume she is with her husband, he knows. And her husband, so shamed from earlier today, will not come near her chambers tonight. They have nothing to worry about, save their own desires.

 

He watched as her senses return, as her sharp mind catches up with her body and she comes back into herself. She stares at him a moment longer before leaning up and recapturing his lips with hers. They kiss for a long minute, drinking each other in before she pulls away.

 

“I would have you inside me, brother.”

 

He pauses, stares at her for a second and then nods his head. Too hastily, it would seem, because as soon as Lucrezia sees it she lets out a soft laugh.

 

He pushes the rest of his pants away, disregarding them as soon as he is rid of them, before he climbs back to her. She lies back as he comes closer, allowing him to crawl over. Her legs fall open again, ready for him, waiting for him.

 

He presses into her slowly, taking in every detail of his new sin. She is hot, so tight around him that he feels overwhelmed by it. His memory of being inside of her is nothing to the real thing – to the revelation of having her all around him, holding him there with her.  

 

Her fingers dig into his shoulders, the same way they had Alfonso’s earlier in the day. But now she is looking right at him, up at him as he thrusts into her. With every push she gasps a little, but she only breaks his gaze to lean forward and catch his lips again.

 

They climb together now, caught up in the movement, in pressing their lips together, in desperately clutching at each other with their hands. Her heels press into his thighs, pulling him in as deep as he can go. She rocks against him in time with his thrusts, lets out little moans every time he hits the right spot inside her.

 

Cesare’s heart is beating wildly. He feels overcome with the reality of being with her, of knowing that she wants him here as much as he wants her. He can feel the ecstacy building within him, the promise of sweet release – like the threat of falling from a cliff or finally beating an opponent. He speeds up, pushing into her more harshly as he chases the feeling. She’s right with him, as well – her breathing is getting quicker, she’s rocking with him and under her breath she murmurs urgent things, like ‘ _more, more, more_.’

 

They come together, a beautiful release as she shakes around him. He feels himself empty within her, washing away any remaining traces of another man. She is his again, he thinks, and everything is as it should be.

 

For a few moments, the two stay still in the middle of the bed. Cesare on top of her, pressing her into the bed. He pulls out of her though, pauses again – making sure his weight isn’t still resting on her before he presses another kiss to her lips and falls to the side. He rolls onto his back, and feels a thrum of pleasure when Lucrezia rolls towards him, pillowing her head on his chest. Her hand moves to play gently with his nipple, which jumps under the attention.

 

“Stay and sleep here tonight,” she whispers to him, her voice already softer than before. She seems tired now – and with her days activities he can’t begrudge her that. He feels exhausted as well, his heart has still not slowed, but the rest of his body is screaming for sleep.

 

Lucrezia is watching him, waiting for his answer.

 

“I will stay as long as I can, sis.” He says, pressing a kiss to the crown of her hair, stroking her hair out of her eyes.

 

They manoeuvre under the bedclothes when their skin has cooled enough, and Lucrezia falls asleep quickly, her head still resting on him. He will have to leave some time in the early morning, before the rest of the house rises to prepare for the next day. He wishes he could stay with her as long as she would have him. But such is the curse of their blood that he should love her so and be condemned for it. God would of course put her into his life, so pure and perfect, just so that he could spoil her. Cesare never stood a chance, and his perversion would ruin his sister.

 

He presses another kiss to Lucrezia head and then closes his eyes. He will at least have these few hours to share with her.

 

It is such a sweet sin.

 


End file.
